Process for producing lubricating oil



Se'pt. 18, 1934. R. QOSTERSTROM 1,973,824.

PROCESS FOR PRODUCING LUBRICATING OIL Filed Feb. 25. 1932 LWasher' .SZu dye Patented sept. 1s, 1934 UNITED STATES PATENT OFFICE.

Rudolph C. Osterstrom, Chicago, Ill., assignor to The Pure Oil Company, Chicago, Ill., a corpora- Application February 25, 1932, Serial No. 595,152

7 Claims. (Cl. 196-78) Y This invention relates to an improved hydrocarbon lubricating oil and process for producing the same, and an object of the invention resides in the production of an improved lubricating oil which, when blended with lubricating oils produced by ordinary methods of manufacture, results in materially lowering the pour test of ordinary lubricating oil, without requiring expensive treatment of the latter oil to produce a free owing product at low `temperatures.

In my previous co-pending applications for the manufacture of a blending oil having the properties of reducing lubricating oil pour points, I have used various fractions obtained from the vapor phase cracking of oils into gasoline as a base material for treatment with aluminum chlo-` ride, as set forth in my co-pending applications bearing Serial Numbers 576,650, 575,871 and 576,127. I now find that an improved product is obtained through the use of wax distillate. In the operation' of re-distilling a wax distillate by cracking, in order to make it suitable for pressing, a non-pressable residue is left which, when mixed with a fraction of a vapor phase cracked distillate of desired boiling range treated with a small percentage by weight of aluminum chloride, produces a superior blending oil having the desirable properties above set forth.

For a further understanding of the invention, reference is to be had to the following description and the accompanying drawing, wherein the figure illustrates diagrammatically the apparatus and steps of operation used in carrying out the present invention.

In the drawing, the numeral l designates a working tank adapted to receive a suitable quantity of a cracked distillate varying in boiling range from thatlof ordinary gasoline to gas oil or so-called recycle stock for cracking systems. This distillate is obtained by the cracking of high boiling hydrocarbon oils, into low boiling oils having approximately the boiling range of gasoline. For example, the distillate may have a boiling range of from 420 to 700 F. although lighter distillates of gasoline boiling range may be used. As is well known, such cracked distillates contain a high percentage of unsaturated hydrocarbons depending upon cracking reaction temperatures and I preferably use this distillate as it is obtained directly from a vapor phase cracking system but have employed advantageously recycle oils obtained from liquid phase cracking systems.

This distillate is passed from the tank 1 to any suitable type of still 2 which is heated, for instance by a'burner or burners 3. While in the still 2, the distillate is heated sufficiently to drive 'od as an overhead vaporous product approximately 30% of the oil introduced into the still.

This vaporizable overhead distillate, composed of lighter ends, is transferred by means of a line 4 to a condenser 5 and received within a tank 6 as a motor fuel. The residue, composed of approximately of the oil introduced into the still 2, is removed from the bottom of the still 35 by way of a line 7 and is introduced into a mixing tank 8. Also connected with the tank 8 is a pipe line 9 leading from a tank 10 which contains a wax distillate residue. This wax distillate resi- A due is obtained from standard operations pro- (0 duced by the re-running or re-distilling of ordinary wax distillateito super-heat or crack the same whereby through a change in its wax structure to make it suitable for pressing, and it is the residue left after the re-running or re-distilling of this wax distillate that is contained in the tank 10. It is believed that this waxy material is not appreciably dehydrogenated but may comprisel non-pressable isoparains. The residual oils removed from the bottom of the still 2 and 30 the wax distillate residue is delivered tothe mixing tank 8 in such proportions that the said tank 8 will contain a mixture composed of approximately 10% of the residual oils withdrawn from the still 2 and 90% of the wax distillate bottoms, 85 these proportions, however, are subject to considerable variation, and with certain oil, the mixture in the tank 8 may be approximately 50% of the wax distillate residue to 50% of the unsaturated cracked stock or distillate.

This mixture is then transferred by way of a pipe line 11, or other suitable means, to a still 12 heated by means of burners or the like 13 and to the mixture inthe still 12 there is added approximately 2% by weight of aluminum chlo- 95 ride, AlzCls. The mixture is preferably agitated while it is being heated by means of a stirrer or its equivalent 14 which may be driven by means of a motor 15. The distillation in the still 12 takes place at a temperature varying between 250 F. 100 to 500 F., which permits the-lighter compounds in the oils to pass overhead by way Aof a line 16 to a condenser and storage tank, leaving a residual oil of desired viscosity in the still following the operation. In this heating operation, I employ the wellknown Friedel-Craft reaction.

Theresidual oil vof this distillation is transferred by way of a line 17 to a washer 1 8 to remove the aluminum chloride, leaving a relatively viscous new synthetic oil stock which may be later received within a tank 20. This oil stock is then preferably re-distilled in a still 21 under non-cracking temperatures and this latter distillation step is carried out so as to take overhead 5 as a vaporizable product approximately 25% of the oil stock, leaving a residue in the still 21 and the remaining viscous residue is then transferred to a storage tank 22 as the desired end product.v I have found that this product when added, in proportions as low as .5% by volume, to a lubricating oil having a pour test as high as 25 to 30 F. lowers the pour point of the resulting blend to as much as 0 F.

Depending on the quality of the wax distillate residue and the quantity of the cracked distillate, the percentages above specified may vary somewhat and still produce a satisfactory product. I have found, however, that the best wax distillate residue to use is that secured from the re-running of wax distillate from Pennsylvania grade crude oil. Anywax distillate left as a residue of a re-running operation can be used but, ordinarily, does not give a final product with as good pour reducing properties as that obtained from the Pennsylvania Wax distillate.

While I prefer to employ aluminumchloride as the catalyst for increasing the viscosity of the oils distilled therewith, yet it will be understood that I may employ any metallic halide having this function, and the expression aluminum chloride as set forth in the claims is intended to cover such equivalents.

What is claimed is: i

1. The process of producing a hydrocarbon lubricating oil which comprises, subjecting residual oil obtained from cracking distillation of wax distillate mixed with unsaturated oil derived from vapor phase cracking of gas oil to distillation in the presence of a catalyst containing a Ametallic halide, removing the catalyst from the product resulting from said distillation, and redistilling said product to remove the lighter fractions thereof to obtain a lubricant residue.

2. The process of producing a pour test reducing blending oil for hydrocarbon lubricating oils which comprises, producing a mixture composed of residual oil obtained from cracking distillation of wax distillate and unsaturated vapor phase cracked hydrocarbon oil derived from gas oil cracking and aluminum chloride, subjecting said mixture to non-cracking distillation, removing the aluminum chloride from the mixture following such distillation, and redistilling the aluminuml chloride free mixture to remove low boiling fractions to obtain a lubricant residue.

3. 'I'he method of producing a blending oil for lowering the pour test of hydrocarbon lubricating oils which comprises, producing a mixture composed of residual oil obtained from cracking distillation of wax distillate and unsaturated oil derived from vapor phase cracking of gas oil, subjecting said mixture while in the presence of aluminum chloride to non-cracking distillation, removing the aluminum chloride: from the' mixture following such distillation, and` finally redistilling the mixture following the removalof the aluminum chloride to free the blending oil from low boiling compounds.

4. The method of producing a blending oil for reducing the pour point of hydrocarbon lubricating oils by admixture therewith which comprises,

Lav/e824 producing a mixture composed of residual oil obtained from cracking distillation of wax distillate and a distillate derived from vapor phase cracking of gas oil, distilling said mixture at temperatures of the order of 250 F. in the presence of a small percentage of aluminum chloride, removing low boiling compounds from the mixture, removing the aluminum chloride from the residual oils of such distillation, and then redistilling said oils following the removal of the aluminum chloride to further remove lowl boiling compounds, the residue of such final distillation constituting the blending oil.

5. The method of producing a blending oil for reducing the pour point of hydrocarbon lubricating oils by admixture therewith which comprises, producing a mixture composed of approximately from 50% to 90% residual oil obtained from cracking distillation of wax distillate and 50% to 10% of a distillate derived from vapor phase cracking of gasloil composed largely of unsaturated hydrocarbons, subjecting said mixture to redistillation in the presence of approximately 2% by Weight of aluminum chloride, removing low boiling compounds, washing the residual oil of such distillation to remove the aluminum chloride, and then redistilling the residual oil to further remove low boiling compounds, the residual oils of such ,final distillation constituting the desired blending oil.

6. The method of producing a synthetic blending oil for the purposes set forth which comprises: producing an oil mixture composed of a non-pressable residue obtained from the distillation of wax distillate and a vapor phase cracked distillate having a boiling range higher than that of gasoline, subjecting said mixture to noncracking distillation at temperatures of approximately 250 F. while in the presence of aluminum chloride, removing low-boiling compounds from the mixture during such distillation and condensing and collecting the same, separately removing from the zone of distillation the residual products consisting of the higher boiling oils and aluminum chloride, removing the aluminum chloride from the residual products,`and redistilling said products to additionally deprive the same of undesired low boiling compounds, the residual products of such final distillation constituting the desired blending oil.

7. The method of utilizing non-pressable residues obtained from distillation of wax distillate, which comprises producing a mixture composed primarily of such residues and secondarily of a vapor phase cracked distillate having a boiling range between that of gasoline and fuel oil, subjecting said mixture to distillation at temperatures of the order of 250 F. while in the presence of approximately 2% by weight of aluminum chloride, removing low boiling compounds from the mixture during such distillation and condensing and collecting the same, separately removing from the zone of distillation the residual products consisting of the higher boiling oils and aluminum chloride, removing the aluminum chloride from the residual products, and redistilling said products to additionally deprive the same of low boiling compounds, the remaining products of such final distillation constituting the desired blending oil.

RUDOLPH C. OSTERSTROM. 

